Internal combustion engine



May 17, 1938. H; KREB 2,117,433

INTERNAL COMBUSTION ENGINE Filed Dec. 31, 1932 Patented May 17, 1938 I UNITED STATES PATENT OFFICE INTERNAL COMBUSTION ENGINE Henry Krebs, Detroit, Mich., assignor to Packard Motor Car Company, Detroit, Mich, a corporation of Michigan Application December 31, 1932, Serial No. 649,698 12 Claims. (01.123-188) This invention relates to internal combustion The valve stem extends into the cylinder block engines and more particularly to valve closing and a tappet member l8, which is operated by a mechanism. moving part of the engine, such as a cam (not Engine poppet valves are usually returned to shown), engages the projecting end thereof.

and held in closed position by coil springs formed The structure so far described is conventional 5 of wire and are opened by mechanisms actuated with most four cycle internal combustion engines by a moving engine part, such as a cam. It is and a further description and showing thereof well recognized that wire springs surge during is not deemed to be necessary. some periods of the engine speed, such periods Associated with the valve stem and the cylinvarying in accordance with the spring characterder block is provided mechanism for automaticall0 istics and other factors. Spring surging is mainly returning the valve to seated. position and for 1y undesirablebecause it causes uncertain valve maintaining it in such. position until the tappet timing, develops noise due to the striking tomechanism again operates to open the valve, and gether of adjacent coils and causes failure of the it is the main purpose of this invention to pro- 5 spring due to fatigue. vide a form of automatic mechanism where- An object of this invention is to provide valve in there will be no surging action during closing and seating mechanism which will opoperation. As one means of carrying out this crate without surging. purpose, I provide mechanism which consists of Another object of the invention is to provide a coil spring l9 and a resilient mass arranged 20 a valve closing and seating mechanism which in aligned relation and surrounding the valve 20 comprises a resilient mass. stem. The spring engages a retainer 2| which is A further object of the invention is to provide held on the valve stem by a key 22 and the yielda valve closing and seating mechanism which is able member 20 has a cap 23 extending over each comprised of a coil spring and a resilient mass. end thereof. The under portion of the cylinder Other objects of the invention will appear block is formed with a recess 24 into which one 25 from the following description taken in connecend of the resilient mass 20 extends and is seated tion with the drawing, which forms a part of this and the upper end of the spring bears against the specification, and in which: i cap covering the lower face of the mass. The

Fig. 1 is a fragmentary sectional view of an spring I9 is assembled so that it is compressed engine with which is associated a valve having sufiiciently to move the key and the stem downclosing mechanism associated therewith which wardly to seat the head of the valve and under forms the subject matter msinvention such circumstances the resilient mass, preferably Fig. 2 is a similar view showing a modifie (m1"m a*rubbel ring is also assembled under some comof valve closing mechanism; pression.

Fig. 3 is a perspective view of a modified form When the tappet is moved upwardlyto gpen of rubber member which forms a part of the valve the valve, the spring and the rubber mass are closing mechanism of the type shown in Fig. 1. further compressed. The mass has the charac- Referring now to the drawing by characters .teristic of cushioning the movement of the spring of reference, l0 indicates a conventional form of and, in this manner, the action of the spring is 40 cylinder block for an internal combustion engine more gradual than it woud be if no rubber mass 40 of the four cycle type in which is formed a maniwere present so that any tendency to surge is fold, as indicated at H, through which the fuel substantially eliminated. Another factor in concharges can pass intov or the exhaust can pass nection with this type 'of valve closing mechanism from the explosion chamber. An opening I! tending to prevent surging is the fact that, with leads through the end wall I 3 of the cylinder a rubber mass forming an axial portion of the 45 structure for establishing communication between closing mechanism, & Sho t length of any One the manifold and the combustion chamber 9 type of coil spring n be us d W u ha thereabove, a portion of the wall !3 being formed the Stroke of the Valve or nc eas n t e maxito provide a valve seat M. The cylinder strucmum spring stress.

ture is also formed with a guide portion IS in In Fig. 3, I have shown a modified form of rub- 5 which is pressed a sleeve bearing "5 in which the her mass 20 which has a serrated upper end 25 to stem of a poppet valve I1 is arranged to reciprodecrease the compression resistance. If desired, cate. The poppet valve has the usual head porthis pressure resistance can be decreased by aplution which is arranged to engage with the seat rality of radially extending openings 26 formed in H to. close the opening l2. the rubber mass.

operates with a retaining key 33 extending through a slot in the lower end of the valve stem and the upper end of the yieldable mass is covered by a cap 34 which seats in the recess'zl of the cylinder block. The mass 30 is of cylindrical form and is provided with a peripheral groove 35 which spirals from one end thereof to the other. The coil spring 3| is formed preferably of flat stock and is wound spirally around the periphery of the mass intermediate the groove and is bonded thereto, under expansion, preferably along its entire length, in a suitable manner such as by vulcanizing. The valve stem extends through an opening in the cylindrical yieldable mass, which is preferably rubber, and the mass is placed under initial axial compression when it is associated in operative relation with the valve and engine.

In this instance, the rubber is further compressed 1 upon opening movement of the valve by means of the tappet, and dueto its inherent characteristics will return the valve to seated position and so maintainit until the next opening actuation of the valve by the tappet. The spring serves the purpose of binding the mass to prevent undue deformation and so that the compression of said mass upon opening of the valve is resisted beyond that which would normally occur.

With the valve closing mechanism herein described there will be substantially no surging action during valve operation.

Although the invention has been described in connection with a specific embodiment, the principles involved are susceptible of numerous other applications which will readily occur to persons skilled in the art. The invention is therefore to be limited only as indicated by the scope of the appended claims.

What I claim is:

-1. In an engine having a valve adapted to be reciprocated at a high frequency, closing means for the valve comprising a rubber member telescoping the valve stem and stationarily anchored at one end, and a coil spring telescoping the valve stem and having one end anchored axially relative thereto, said rubber member being under axial compression and co-acting with the spring -.to reduce the surging thereof normally occurring in high frequency operation of the valve stem.

2. In a valve mechanism for internal combustion engines, a valve, a valve stem, valve closing devices having a rubber mass surroundinga pcr= tion of the valve stem, and means for assembling the rubber mass in a compressed condition with the'valve stem when the valve is closed, and in a relation opposing any valve opening movement.

3. A construction for internal combustion engines comprising a valve for rapid reciprocating movement, means for moving the valve to its closed position, comprising a spring and a mass of yielding resilient material arranged in series therewith to damp the surges of the spring.

4. In an engine, the combination with a cylinder block and a poppet valve having a stemextending through the block, of valve closing means comprising a rubber mass surrounding a valve stem and seated at one end against the block and means anchoring the other end of said rubber mass axially to the valve stem in a relation opposing opening movement of the valve, said mass coacting with the spring to change its normal frequency when operated at high speed.

5. In an engine valve operating mechanism, valve closing means comprising a helically coiled wire section and a rubber section, said sections being arranged in series so that the rubber section dampens surging of the spring section when operated at ahigh rate of speed.

6. In an engine valve operating mechanism, valve closing means comprising a. coil spring and a rubber mass arranged in'axial abutting relation, said rubber means influencing said spring to prevent surging thereof when operated at high speed. Y

7. In an engine valve operating mechanism, valve closing means comprising a rubber mass, and a coil spring secured under tension around said rubber mass, said mass preventing surging of the coil spring at any operating speed.

8. In an engine valve operating mechanism,

valve closing means comprising a rubber mass in compression, and a coil spring under expansion.

9. In an engine valve operating mechanism, valve closing means comprising a cylindrical rubber mass under axial compression and a helical coil, said mass being associated with said coil in a relation to reduce the normal surging thereof when operated at high speed.

10. In an internal combustion engine having an engine block provided with a passage for gas, a poppet valve movable to and from seating position to close and open said passage, and yielding means for moving said valve to seating position, said yielding means including a coil spring and other deformable means acting in series between said valve and said engine block, said deformable means being subject to deformation of less extent than said coil spring.

11. A construction for internal combustion engines comprising a valve for a rapid reciprocating movement, and means for moving the valve to seating position comprising a spring and a mass of yielding resilient material including rubber arranged in series therewith to damp the surges of M I the spring. v

12. In an internal combustion engine having an engine block provided with a passage for gas, a

deformation of less extent than said coil spring.

HENRY KREBS. 

